As the hardware of mobile terminals and extended memory develop, a user can store a large amount of files at a mobile terminal and its extended memory and search these files via the mobile terminal. To protect privacy and the security of the files, the user may wish to encrypt the files.
Encryption can be a particular type of algorithm to change the original data of a file, thus preventing an unauthorized user having obtained the encrypted file from knowing the content of the file because he does not know the decryption method. Typically, these files include text documents, programs, images, and videos. Regarding video files, existing video file encryption method can be used to perform encryption. In particular, an existing video file encryption method can include, first encrypting the whole video file to obtain an encrypted video file, and then moving the encrypted video file from its original storage location to a designated storage location.
It is discovered that this existing technology has at least the following problems.
Video files are the largest files among all the files. When the designated storage location is in a disk partition different from the disk partition including the original storage location, the speed of moving the encrypted video file can be very slow, affecting the encryption efficiency.